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1.
洪天求 《吉林大学学报(地球科学版)》1995,(1)
德国泥盆纪的层孔虫十分繁盛,不同形态、不同规模的层孔虫礁体广泛发育于台地内部、台地边缘和深海盆地内的火山周日。块状层孔虫是主要的造礁生物,四射珊瑚也参与了造礁,但数量极少。礁区岩相分异明显,盆地相、礁前相、礁核相和礁后泻湖相清晰可辨。部分礁体,如布瑞隆环礁显示清楚的初殖、拓殖、繁殖和衰亡四个演化阶段。层孔虫礁的主要繁盛期为吉维特期-弗拉斯期。德国泥盆纪生物礁的基本特征类似于加拿大同时期的生物礁,但在德国泥盆纪的礁灰岩杂体内至今尚未发现有经济价值的石油和天然气。这可能与莱茵海西地槽复杂的地质发展史有关。 相似文献
2.
洪天求 《长春地质学院学报》1995,25(1):24-30,T001
德国泥盆纪的层孔虫十分繁盛,不同形态,不同规模的层孔虫礁体广泛发育于台地内部,台地边缘和深海盆地内的火山周围。块状层孔虫是主要的造礁生物,四射珊瑚也参与了造礁,但数量极少。礁区岩相分异业显,盆地相,礁前相,礁核相和礁后泻湖相清晰可辨。部分礁体,如布瑞降礁显示清楚的初殖,拓殖,繁殖和衰亡四个演化阶段。层孔虫礁的主要繁盛期为吉维特期-弗拉斯期。德国泥盆纪生物礁的基本特征类似于加拿大同时期的生物礁,但在 相似文献
3.
通过对华南泥盆纪生物礁现有资料和作者获得的实际材料的分析研究,编制了华南早、中、晚泥
盆世生物礁分布图。华南泥盆纪生物礁最早出现在埃姆斯晚期,分布层位由西南向北东逐渐上升。华南泥盆纪
生物礁分布和演化具有 3方面的特征:(1)不同类型生物礁演化差异很大:浅水礁变化最大,台缘礁变化次之,
深水礁几乎没有变化;(2)主要造礁生物随时间演替明显:床板珊瑚 ( 埃姆斯期)→床板珊瑚、四射珊瑚和层
孔虫 ( 艾菲尔期)→层孔虫和四射珊瑚 ( 吉维特期)→层孔虫 ( 弗拉期)→菌藻类 ( 法门期) ;(3)生物礁数
量和规模在吉维特期出现峰值。研究表明:华南泥盆纪生物礁的发育受区域和全球性因素的共同制约,其中温
度、大气中 CO2 分压 ( PCO2)和植被-森林生态系等全球性因素对华南泥盆纪生物礁有重要影响。 相似文献
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蔡雄飞 《沉积与特提斯地质》1990,10(2):34-37
层孔虫是一类底栖固着的海洋生物,从寒武纪晚期到白垩纪地层中都有分布,但最盛时期是泥盆纪,不但属种数量急剧增加,而且分布亦很广泛。由于层孔虫本身对环境介质极其敏感,不同的环境可以有不同的形态,因而可以成为判断沉积环境的标志。一、层孔虫的各种形态根据对湘中、西秦岭等地泥盆纪大量层孔虫属种骨骼分析和统计,层孔虫的各种形态大致可以分为几类: 1.块状层孔虫类常见的有柱状、球状、半球状(图1)。它们的个体范围变化很大,小者十几厘米,大者可达数米。它们在大多数情况下可以坚固地附着海底向上生长,具有较强的抗浪性和造礁能力。 相似文献
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自泥盆纪埃姆斯期, 广西受陆内裂陷影响, 形成碳酸盐台地与台沟间列的构造格局.吉维特期开始, 六景及相邻的黎塘一带逐渐形成孤立台地的沉积背景.吉维特期, 六景剖面的民塘组为以竹节石为特色的礁前斜坡生态系, 尽管目前没有出露生物礁, 从礁前角砾岩可以恢复曾经存在的礁生态系.而黎塘一带塘家湾组为以珊瑚、层孔虫、腕足类为主要特色的台地生态系.弗拉斯期, 六景剖面的谷闭组则为少量珊瑚、腕足、层孔虫为特色的局限-半开放台地生态系.黎塘一带的桂林组仍为以珊瑚、层孔虫、腕足类为主要特色的台地生态系.六景、黎塘地区自法门期开始发生生态系突变, 六景剖面的融县组和黎塘一带的东村组发育藻礁丘或藻席为特色的藻生态系.该生态系的突变是F-F生物群集绝灭造成的生物类群突变的结果.生态系的特征也与吉维特-弗拉斯期烃源岩的形成、演化密切相关. 相似文献
7.
古生代层孔虫的生态特征 总被引:3,自引:0,他引:3
《地层学杂志》1986,(2)
<正> 古生代尤其是泥盆纪层孔虫是重要的造礁生物,研究它的古生态及与生物礁之间的关系十分重要。近二十多年来,随着国际上在一些生物礁内发现了许多重要的油气藏和礁控多金属矿产之后,对生物礁的研究越来越引起人们的重视。我国南方生物礁发育,分布广泛。为了解层孔虫的古生态特征,对生物礁的有关概念简述如下: 相似文献
8.
<正> 塔里木盆地生物礁目前主要发现于轮南、塔中、巴楚等地区(图1),层位集中于中奥陶统的一间房组、上奥陶统的吐木休克组和良里塔格组,并以一间房地区的生物礁发育最完整。初步研究结果认为,生物礁主要呈长条状分布于两种沉积环境:(1)碳酸盐台地向台地斜坡过渡的台地边缘环境;(2)碳酸盐台地内的地形由平坦向较陡处转折的地带。造礁生物的含量可达30%以上,上奥陶统中主要有海绵、苔藓虫、层孔虫、珊瑚、托盘类、蓝绿藻、管孔藻等。中国以往仅有在陕西渭河以北地区、浙赣交界地区和湖北地区发现奥陶系生物礁的报道,本次发现结束了塔里木盆 相似文献
9.
首次发现西藏安多县东巧地区晚侏罗世生物礁,造礁生物以层孔虫和六射珊瑚为主,其中,层孔虫可分为枝状、筒状和块状三种类型,它们多以原地生长状态保存.礁岩石学特征研究表明,礁岩可分为筒状-枝状层孔虫障积岩、枝状层孔虫障积岩、筒状层孔虫障积岩、筒状-块状层孔虫障积-骨架岩和筒状层孔虫-六射珊瑚障积-骨架岩.礁体类型可分为筒状-枝状层孔虫障积岩隆礁、枝状层孔虫障积岩隆礁、筒状层孔虫障积岩隆礁、筒状-块状层孔虫障积-骨架岩隆礁和筒状层孔虫-六射珊瑚障积-骨架岩隆礁,礁体的演化均经历了奠基阶段、发育阶段和衰亡阶段. 相似文献
10.
层孔虫(stromatoporoid)一词由德国地质学家Goldfuss在1826年创立,因其表面呈纹层状而得名。层孔虫属于海绵动物,是一类营群体生活的海洋底栖固着生物,形态多样,大小从几厘米至数米不等,通常生活在温暖、清澈、盐度正常和光照条件好的浅海中,常与珊瑚、藻类共生而形成生物礁,是重要的造礁生物之一。层孔虫起源于早奥陶世,繁盛于泥盆纪,进入石炭纪基本消失,但在晚三叠世复又出现,并于晚侏罗世得到进一步发展,最终在早白垩世末彻底灭绝。本文在回顾总结了层孔虫研究历史与研究现状,指出层孔虫的研究历史大体经历了零星研究阶段(1826—1950年)、系统研究阶段(1951—1971年)和集成创新阶段(1972年至今),主要介绍了层孔虫的形态与构造、系统分类、起源与演化、生物间的共生关系和层孔虫在古环境重建中的应用,在此基础上提出了目前层孔虫研究中存在的3个主要问题: 缺少明确、完善且统一的生物分类方案;起源的时代存在争议,演化过程中存在奇怪的“间断”现象,早石炭世至晚三叠世的地层中未见相关化石记录;与各种共生生物之间的关系不甚清楚。层孔虫在古生物学的研究中是不可缺少的一个门类,它的各种形态、习性特征在恢复古地理、重建古环境的过程中具有重要意义。 相似文献
11.
Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
12.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引:4,自引:0,他引:4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
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Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozach Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
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正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level 相似文献
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正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7), 相似文献
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正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci- 相似文献
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正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli- 相似文献
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正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.) 相似文献
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正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861 相似文献